Corps marks major milestone on IHNC Surge Barrier project

Published Oct. 29, 2009

Last "soldier" pile provides second Mississippi River Gulf Outlet closure

NEW ORLEANS – On Oct. 21, the U.S. Army Corps of Engineers marked a major milestone in its risk-reduction efforts when the Corps pounded the last of 1,271 66-inch spun-cast piles that make up the main structural element of the Inner Harbor Navigation Canal (IHNC) Lake Borgne Surge Barrier into the ground.

In just five months and twelve days, crews working two pile drivers, two shifts a day, six days a week, drove the 144-foot-long concrete piles deep into the mud and clay layers just east of the confluence of the Gulf Intracoastal Waterway (GIWW) and the Mississippi River Gulf Outlet (MRGO).

The massive $1.3 billion surge barrier, the largest of its kind in the world, is a key feature of the greater New Orleans Hurricane and Storm Damage Risk Reduction System. It will lower the risk of storm damage to some of the region’s most vulnerable areas – New Orleans East, metro New Orleans, the Ninth Ward and St. Bernard Parish -- by reducing surge generated from the Gulf of Mexico and Lake Borgne.

"This day highlights the tremendous progress we’ve made in a very short time, but there is much more work to be done," said Col. Robert Sinkler, commander of the Corps’ Hurricane Protection Office. "Since we drove the first pile in May, our team has worked around the clock and we finished this portion of the barrier nearly two months earlier than anticipated. We are committed to meeting our 2011 goal for providing 100-year protection to the citizens of Southeast Louisiana."

The main portion of the barrier wall consists of 66-inch spun cast piles, called soldier or vertical piles, 18-inch closure piles, 36-inch steel batter piles, (to resist lateral movement), both precast and cast-in-place deck sections, and a parapet wall. The 1.8-mile structure will also include three navigation gates. With the exception of the parapet wall, all other elements of wall construction are under way and all will be completed by this time next year.

At the north and south end of the structure, 26-foot T-walls will tie into the perimeter protection in New Orleans East and St. Bernard. Construction on these tie-ins will begin this winter and should be in place before the start of the next hurricane season. Piles for the T-walls are already in production.

Work is also progressing on the barge gate, a 150-foot navigation gate to be opened for traffic next spring. On 24 – 26 Oct., crews successfully executed a continuous, 35+ hour underwater pour of nearly 5,000 cubic yards of concrete. In the Tremie Concrete method, concrete is placed below water level through a pipe, the lower end of which is kept immersed in fresh concrete so that the rising concrete from the bottom displaces the water without washing out the concrete content (See photo on the top of page 3). This was part of construction of a cofferdam, an enclosure within a water environment built to allow water to be displaced by air for the purpose of creating a dry work environment. The cofferdam will be dewatered next week, and work will begin casting the barge gate sills. Construction of the 56-foot wide Bayou Bienvenue gate will begin in spring 2010, along with work on the 150-foot sector gate in the GIWW.

Shaw Environmental and Infrastructure of Baton Rouge is the prime contractor for the project. There are 55 small business contractors working for the team, 44 of which are Louisiana firms. Every day about 350 people work on the job site, with up to about 2,000 others working full- or part-time to support the effort.

The IHNC Lake Borgne Surge Barrier is the largest design-build civil works project in Corps of Engineers history.

Note to Media: High-resolution versions of photos and graphics are available by contacting the Public Affairs Office at (504) 862-2080 or via e-mail to You can also view more pictures on Team New Orleans’ Flickr site,

Release no. 09-032